A Method of Time-varying Harmonic Detection Based on the Wavelet Neural Network
DU Tian-jun · Proceedings of the CSEE · 2008
There are many time-varying harmonics caused by the non-linear instruments that convert or invert the current or voltage of the power system. A novel method based on wavelet neural network (WNN) is proposed. Using the time-frequency focus characteristic,the information of time-varying of harmonics can be gotten. The approach and convergence capability are improved by the wavelet transform characteristic of auto-adapt dividing time-frequency plane. And the precept of the WNN characters selection is given,and the algorithm to train the network is proposed. The efficiency of detection harmonics by WNN has been analyzed,and the performance of different methods is compared. The simulation result illustrates the effectiveness of the presented methods.